Day 55. Mexico 2022. The last day

I left Cabo San Lucas at 6:30 am, because I had to drive two hours to La Paz to join a snorkeling excursion to the island of Espíritu Santo, about an hour boat ride north of La Paz, in the Sea of Cortés. I got there with plenty of time to get breakfast and find a good place to park just off the malecón. As is often the case I was the first one there and had a chance to chat at length with our guide, a young woman named Nish (short for Nishma, an Arab name but she is 100% chilanga; the name probably comes from the telenovela that was in vogue at the time she was born). The group assembled slowly, and on the way we had to pick up a couple at their hotel, but finally we were ready and my other tocayo, Captain Gerardo, rushed us across to the south end of the island.

I was fascinated by the geology, which is at the same time simple and complex. It is a slightly tilted block where an enormously thick ignimbrite is exposed, to which I will hereafter refer to as the Espíritu Santo Ignimbrite. There is enough exposure to ascertain that the substrate was a series of basaltic lahars, happily stacking layer after layer, when the first of the ignimbrite eruptions took place. A few months went by, during which lithic conglomerates were deposited, and then things really got going. I am going to say that over a short period, perhaps of a few days or weeks, one pyroclastic flow followed another until a good 300 m of ignimbrite accumulated. But the pumice and glass shards remained hot (say 300⁰ C) for an extended period of time, and under the enormous accumulated weight the volcanic glass shards started deforming, compacting, and welding which gave the unit an astonishing variety of colors and aspects, ranging from the light pink of the unwelded portions, through the dark pink of the partially welded portions, to the black of the strongly welded portions, to the brick red of the vapor-phase altered portions. This is what one would call a cooling unit, but to complicate things the cooling unit sometimes splits into two and perhaps three cooling units. I wish I could bring my students here, because I have rarely seen such a clear example of the apparent complexity of this type of volcanic deposit.

The snorkeling was great, although we didn’t see any exotic sea mammals. Colorful fishes were aplenty, however, and at some point it fell that we were immersed in a giant aquarium. We made three swims, and in the third one we were expecting to be joined by some juvenile sea lions that were sunbathing on top of a pointy seamount/reef. But the kids were playing with their cell phones and feeling lazy, so eventually Dad got into the water and with a suitable tone of voice told us to get lost.

So that is it. I have had my last bit of fun in this trip, peninsula to peninsula, across beautiful Mexico. I have met great people, seen fabulous landscapes, and shared the national obsession with eating delicious food. Try it. You will find that Mexico welcomes you with open arms.

Finis